Shape selective epoxidation of crotyl alcohol with H2O2 in the presence of TS-1

Abstract

The use of alcohols as solvents was investigated for allyl and cis- and trans-crotyl alcohols; methanol was found to be the best solvent for allyl alcohol and ethanol for crotyl alcohol. However, the reaction was possible, using water as solvent, without loss of selectivity of the oxirane, because of triol formation at short reaction times (1–3 h). A number of studies have demonstrated that alkenes can be readily epoxidised by hydrogen peroxide, using the titanium silicalite TS-1. However, it has been found that substitution of the alkene by electron withdrawing groups significantly decreases the reactivity of the carbon–carbon double bond, because the decrease of the electron density renders it less susceptible to electrophilic attack by the oxidant. Although TS-1 has been investigated for the epoxidation of a range of molecules, for example, butene, pentene, hexene, allyl chloride, and allyl alcohol, little attention has been given to the effect of shape selectivity in the MFI zeotype framework in these reactions. In this paper, it is possible to address this aspect and exemplify the shape selective epoxidation, using a range of allylic alcohols. In particular, the shape selective epoxidation of crotyl alcohol is compared and contrasted with the reaction of allyl alcohol in a range of solvents.